What molecule is primarily produced by autotrophs during photosynthesis?

The primary product of photosynthesis in autotrophs is glucose. During this process, autotrophs, which are organisms capable of producing their own food using light energy (such as plants), use carbon dioxide and water in the presence of sunlight to synthesize glucose. The equation for photosynthesis illustrates this: carbon dioxide plus water, in the presence of sunlight, yields glucose and oxygen as byproducts.

While oxygen is generated during photosynthesis and is vital for aerobic organisms, it is not the main product that autotrophs utilize for growth and energy. Glucose serves as a key energy source and is fundamental for the structure and function of the plant, being used in cellular respiration to generate ATP or stored as starch for later use.

In the context of the other options, carbon dioxide is used as a reactant, not a product, and while ethanol is related to fermentation processes, it is not produced by autotrophs during photosynthesis. Therefore, glucose is the correct answer, as it is the primary organic molecule synthesized by autotrophs through the process of photosynthesis.